PDA

View Full Version : New to rotary processing.


Adrian Twiss
12th July 2010, 06:31 AM
I developed my first two pieces of 5x4 in a rotary processor last night. I used a CPE processor. My method was

Film Ilford HP5+ rated at 400 iso
Developer Rodinal at 1:25
Time 5minutes 4 seconds - this was 6 minutes less 15% as recommended by Ilford
Agitation - fast speed alternating direction
No pre soak

Chemical temperatures we about 22.5 deg C

The first sheet came out with streaks due to poor loading. The second sheet was very evenly developed.

However, both sheets were extrememely dense. I don't normally over expose my films so am suspecting over developement.

I would welcome any observations from more those more experienced in rotary processing.

On another note, I find the 2509N sprial a real fiddle to load. Does anyone know if you can use an Expert drum by rolling it along a counter top to agitate it?

Many thank.

Adrian

Trevor Crone
12th July 2010, 07:00 AM
Hi Adrian, I don't know if this is of any help to you but I've developed 8x10 film in a Jobo 2830 drum (2 sheets) rolled on their 1509 roller base and development was fine. This roller base will also take the Jobo Expert drums, I have one but never used it. However I must say I prefer to use a Peterson Orbital processor for 8x10 and the odd sheet of 4x5, but most of my 4x5 is developed in the Combi Plan tanks.

Dave miller
12th July 2010, 07:32 AM
I'm another Paterson Orbital person so can't help with the Jobo question for film work. I do think that you are on the right track when considering agitation as being the cause of your extra density.

Adrian Twiss
12th July 2010, 11:07 AM
Trevor/Dave

Thanks for the replies. I have quite a few sheets to develop. I will keep to the same regime for the next one just to make sure I have not overexposed. Then I will slow the agitation down to see what that does. I neither work I will try pre-soak, despite Ilord's advice not to do so.

Mike O'Pray
12th July 2010, 11:24 AM
I neither work I will try pre-soak, despite Ilord's advice not to do so.

Ilford says that for rotary processing up to 25% less may be needed.

I have a feeling that on Unblinkingeye( the Ed Buffalo site) there is an article on rotary processing and for certain film the reduction was much less than 25% but this is a hazy and possibly wrong memory.

In John Tinsley's book on rotary processing he says that acutance developers lose that effect with rotary processing and he advises using the fast speed or even development.

While he confines himself to Ilford chems he says that he uses the inversion agitation times successfully and puts this down to the effect of doing a pre-soak which he says worked with no adverse effects.

If you try the pre soak it may be that the Ilford reductions of between 15-25% may have to be at least reduced.

Best of luck

Mike

Trevor Crone
12th July 2010, 11:58 AM
Adrian, I always pre-soak my films (roll, sheet) for about 2 minutes before I start development.

I use constant agitation when using the Jobo and the Paterson Orbital, but this is quite gentle so as not to increase density along the films edge, particularly when using the Orbital. I develop 8x10 HP5 (400iso) in Rodinal diluted 1:25 for 12 minutes at 21*C. The negatives are a little on the dense side so I can use them for contact printing and alternative processes.

Mike O'Pray
12th July 2010, 12:47 PM
Adrian, I found the article referred to. it was by someone called John Hicks. What he found to be necessary to obtain the same CI as for inversion agitation was a 25% reduction for HP5+ but a 35% reduction for D100 and only a 15% reduction for D3200.

However in his case these reductions included a one minute pre-soak. None of it involved Rodinal however but it does seem to indicate that HP5+ may need 25% reduction and a pre-soak.

If a pre-soak normally reduces the need to reduce rotary times then this would seem to be in line with your findings and adds credence to needing perhaps more than even a 25% reduction without any pre-soak.

Mike

Bill
12th July 2010, 03:18 PM
Hi Adrian,

Like you I use the Jobo CPE2 for sheet film processing.

I have never used it with Rodinal tending to use ID11 for HP5 Plus.

Couple of things to check. I found at first I was getting very dense negatives. I was tempering the chemicals and pre-soak in the water bath setting the 20 degrees on the thermostat. When I finally did a check what read as 20 degrees actually gave 24 degrees in the water bath so I would check that. I have also read that you should use the slow speed rotation which is what I now use. As for time I find a reduction in the region of 30% on Ilford's time works for me.

Loading the reels can seem difficult at first but with practice it gets easier. (Watch me make a mess of the next one now.):D

I had no success with the Paterson Orbital BUT I had not modified it in the way Dave describes in his article so that may have been the reason.

Keep trying as I am happy with the results I am getting with mine. I am sure you will be too.

Bill

Adrian Twiss
12th July 2010, 04:32 PM
I am very grateful to all of you for your helpful advice. Watch this space.

Keith Tapscott.
12th July 2010, 09:02 PM
I developed my first two pieces of 5x4 in a rotary processor last night. I used a CPE processor. My method was

Film Ilford HP5+ rated at 400 iso
Developer Rodinal at 1:25
Time 5minutes 4 seconds - this was 6 minutes less 15% as recommended by Ilford
Agitation - fast speed alternating direction
No pre soak

Chemical temperatures we about 22.5 deg C

The first sheet came out with streaks due to poor loading. The second sheet was very evenly developed.

However, both sheets were extrememely dense. I don't normally over expose my films so am suspecting over developement.

I would welcome any observations from more those more experienced in rotary processing.

On another note, I find the 2509N sprial a real fiddle to load. Does anyone know if you can use an Expert drum by rolling it along a counter top to agitate it?

Many thank.

Adrian
I don't use Rodinal, but the instructions of my Jobo CPA2 suggest using Tetenal film developers and their times for inverting a small-tank every 3 seconds for rotary-processing.

Their developers come supplied with times for 2 levels of contrast, one for condenser enlargers (Beta = 0.55) and another for diffuse light-source enlargers, (Beta = 0.70).